Rhinitis leprosary.
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Biomedical subjects
Publications and source records attributed to A Moreno.
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We have taken two approaches to the study of the genetics of leucine transport in mammalian cells. First, from a mutant Chinese hamster ovary cell line that has a temperature-sensitive leucyl-tRNA synthetase, we isolated temperature-resistant revertants with increased leucine transport activity. This transport elevation is reflected by increased Vmax values of leucine uptake and unchanged Km values of uptake. The temperature resistance in each revertant appears to result from the increased transport and not from any change in the leucyl-tRNA synthetase. We conclude that in each revertant there is a stable derepression of amino acid transport system L. In a second approach, we started with a Chinese hamster-human hybrid strain formed by the fusion of a temperature-sensitive leucyl-tRNA synthetase mutant hamster cell line and normal human leukocytes. From this temperature-sensitive hybrid strain we selected temperature-resistant hybrids, one class of which we found to have greatly elevated leucine transport activity. We have allowed human chromosomes to segregate from these high-transport hybrids, promoted by the presence of low concentrations of colcemid. The loss of the high-transport phenotype coincides with the loss of a single small human chromosome, which we are attempting to identify by using G-11 and G-banding staining techniques.
Ultrastructural findings in 2 cases of actinic granuloma are presented. The changes observed at the periphery of the lesion and in the elastic fibers, with early stage of damage, were similar to those described in actinic elastosis. Later, an histiocytic reaction which was apparently directed against damaged elastic fibers was observed. The ultrastructure confirms the light-microscopic findings, but does not clarify the etiology of the lesion or its relation to granuloma annulare.
The authors present the clinical and histological findings in a series of 42 liver biopsies from 39 chronic alcoholics treated with cyanamide as aversion therapy. All biopsies displayed characteristic cytoplasmic inclusions in the liver-cells. Fibrosis and disruption of the parenchymal-connective tissue interface were observed in all cases. According to the severity and extension of fibrosis, three stages could be depicted: Stage I. Periportal activity cholangiolar type (ACT), which is defined by cholangiolar proliferation, fibroblastic activation and inflammatory infiltrate, which together cause a blurred appearance of the parenchymal-connective tissue junction. It is the elementary lesion and was observed alone in 26 biopsies. Stage II. Portal-to-portal linkage. It was observed in 10 biopsies, all of which also showed periportal ACT. Three of these came from patients with two biopsies in which transition from stage I (first biopsy) to stage II (second biopsy) was observed. Stage III. Nodular parenchymal regeneration, associated with changes observed in stage I and II. It was found in six patients. The histological picture resembles the biliary type of cirrhosis. There is a clear-cut correlation between the length of treatment and the stage of the hepatic lesion.
We have studied leucine transport in several Chinese hamster-human hybrid cell lines obtained by fusion of a temperature-sensitive line of Chinese hamster ovary cells, ts025C1, and normal human leukocytes. A hybrid cell line exhibiting a twofold increase in L-leucine uptake over that in the parental cell line was found. This hybrid cell line, 158CnpT-1, was temperature resistant, whereas the parental Chinese hamster ovary mutant, ts025C1, contained a temperature-sensitive leucyl-tRNA synthetase mutation. An examination of the different amino acid transport systems in this hybrid cell line revealed a specific increase of system L activity with no significant changes in systems A and ASC. The Vmax for L-leucine uptake exhibited by the hybrid 158CnpT-1 was twice that in the CHO parental mutant, ts025C1. Cytogenetic analysis showed that the hybrid 158CnpT-1 contains four complete human chromosomes (numbers 4, 5, 10, and 21) and three interspecific chromosomal translocations in a total complement of 34 chromosomes. Biochemical and cytogenetic analysis of segregant clones obtained from hybrid 158CnpT-1 showed that the primary temperature resistance and high system L transport phenotypes can be segregated from this hybrid independently. The loss of the primary temperature resistance was associated with the loss of the human chromosome 5, as previously reported by other laboratories, whereas the loss of the high leucine transport phenotype, which is associated with a lesser degree of temperature resistance, was correlated with the loss of human chromosome 20.
2 cases of malignant hidroacanthoma simplex are reported. Prominent ultrastructural findings were sparse tonofilaments and villous-like, interdigitating cytoplasmic processes connected by small desmosomes. Positive intracytoplasmic stain for carcinoembryonic antigen was found in 1 case. Benign and malignant eccrine poromas and hidroacanthoma simplex appear to be related neoplasms on the basis of ultrastructural and immunohistochemical findings.
A 71-year-old man developed multiple subcutaneous nodules during Pseudomonas aeruginosa septicemia. The acute and simultaneous flare of inflammatory nodules in a septic patient appears to be rather specific in Pseudomonas infections. Histological vascular lesions are prominent in the subcutaneous nodules.
We compared the incidence and morphologic appearance of eosinophilic globules in Spitz's nevi, malignant melanoma and compound nevi. Eosinophilic globules were frequently found in Spitz's nevi, specially in those with junctional or compound features. An statistical significant increase of eosinophilic globules was found in Spitz's nevi when compared with malignant melanoma. Eosinophilic globules are not an reliable criteria for a diagnosis of a bening lesion. The use of multiple histologic parameters for differential diagnosis is necessary.
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Two cases of spreading pigmented actinic keratosis are reported. In case number one, an invasive, pigmented squamous cell carcinoma developed in the lesion. Clinicopathologic features include size greater than normal, lateral spread of the lesion, and presence of melanin in dysplastic epidermal cells, dendritic melanocytes and dermal melanophages. Differential diagnosis to be considered includes lentigo maligna, lentigo maligna melanoma and seborrheic keratosis.
We report a case of leiomyosarcoma arising in smooth muscle of scrotum (Dartros muscle). Morphological findings are similar to leiomyosarcomas in other sites. Because of deep location of smooth muscle in scrotal skin, scrotal leiomyosarcomas are deep located tumors lacking the indolent course described in pure dermal leiomyosarcoma.
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